To convert 2.5 inches to millimeters, you will need to use the conversion factor of 1 inch = 25.4 millimeters. This means that for every inch, there are 25.4 millimeters.

Step 1: Write down the given value

First, write down the given value of 2.5 inches.

Step 2: Set up the conversion factor

Next, set up the conversion factor by writing 1 inch over 25.4 millimeters. This will help you keep track of the units and ensure you are converting correctly.

Step 3: Cancel out like units

In this step, you will cancel out the units of inches. To do this, multiply the given value of 2.5 inches by the conversion factor of 1 inch/25.4 millimeters. This will result in the unit of inches being cancelled out, leaving you with only millimeter units.

(2.5 inches) x (1 inch/25.4 millimeters) = 63.5 millimeters

Step 4: Write down the converted value

Write down the converted value of 63.5 millimeters. This is the final answer after converting 2.5 inches to millimeters.

Step 5: Check your answer

To check your answer, you can use a calculator or simply divide the converted value by the conversion factor you used. In this case, divide 63.5 millimeters by 1 inch/25.4 millimeters. This should give you the original value of 2.5 inches.

(63.5 millimeters) / (1 inch/25.4 millimeters) = 63.5 millimeters x 25.4 / 1 inch = 2.5 inches

Step 6: Write the final answer

Write the final answer as 2.5 inches is equal to 63.5 millimeters.

Therefore, to convert 2.5 inches to millimeters, simply multiply the given value by 25.4 millimeters/1 inch. Following these steps will ensure that you accurately convert the unit of length from inches to millimeters.